#include <bits/stdc++.h>
using namespace std;
typedef long long LL;

LL a, b, p;

LL qmul(LL a, LL b, LL p)
{
	LL ans = 0;
	while(b)
	{
		if(b & 1) ans = (ans + a) % p;
		a = (a + a) % p;
		b >>= 1;
	}
	return ans;
}

int main()
{
	cin >> a >> b >> p;
	cout << qmul(a, b, p) << endl;
	return 0;
}